1. Field of Invention
The present disclosure relates to a fluid handling system used for producing downhole fluids. More specifically, the present disclosure concerns a fluid handling system having an electrical submersible pump combined with a compressor.
2. Description of Prior Art
Submersible pumping systems are often used in hydrocarbon producing wells for pumping fluids from within the well bore to the surface. These fluids are generally liquids and include produced liquid hydrocarbon as well as water. One type of system used in this application employs an electrical submersible pump (ESP). Typically ESP's employ centrifugal pumps with multiple stages of impellers/diffusers. These systems are particularly used in wells that produce a large amount of water in ratio to the oil. ESPs are typically disposed at the end of a length of production tubing and have an electrically powered motor. Often, electrical power may be supplied to the pump motor via an ESP power cable.
In many oil wells, gas is also produced with the liquid hydrocarbon. The liquid usually comprises hydrocarbon, and water.
In certain applications the pump intake is positioned above where the connate fluid enters the wellbore, and thus gas may enter the inlet. Most ESP's are designed for pumping incompressible liquids and not gas. If too much gas is delivered to a pump it will lose efficiency because of the compressibility of gas. To overcome this problem gas separators are employed to extract gas from the mixture thereby diverting from the pump inlet. A gas separator separates a mixture of liquid and gas typically by centrifugal force. The liquid flows through a central area into the intake of the pump. The gas is discharged out gas discharge ports into the annulus surrounding the pump. Gas in the annulus collects at the surface of the well and is often introduced through a check valve hack into the production flowline at the surface.
The produced gas may be pressurized if it has insufficient pressure to flow to surface or if the gas is to be re-injected into a subterranean formation. Reinjecting the gas may be for promoting hydrocarbon production from that formation, or it may ultimately be delivered to subterranean storage. An example of a centrifugal gas compressor comprises stages of rotating impellers within stators or diffusers. However, the design is such that compressors compress gas and not pump a liquid. Generally, a centrifugal gas compressor must operate at a much higher rotational speed than a liquid pump.